1. Field of the Invention
The present invention relates to cyclopropane derivatives which are useful in the preparation of antiviral agents and the like, and to methods of preparing such derivatives and also to the intermediates useful in preparation of such derivatives.
2. Description of the Background
Compounds represented by formula (a) infra are known to have potent antiviral activity (JP-A-5/78357). ##STR2## However, the method described for preparation of these compounds in the above publication is a time-consuming process involving the protection of an intermediate followed by a step of deprotection, and is not suitable for industrial-scale production of the compounds. A need therefore continues to exist for an industrially more advantageous method of producing of the above compounds.